查看更多>>摘要：Over the past few decades, the U.S. government and private industry have actively worked to promote global trade. However, sufficient attention has not been paid to updating and improving the corresponding national transportation assets required to take full advantage of the economic opportunities in today's dynamic world market. This paper reviews the growth trends in international trade, including major shifts in the sourcing and distribution of U.S. goods from overwhelmingly domestic systems to increasingly global ones. It highlights the great stresses that these changes in freight movement place on all transport modes, especially those at international gateways, where the modes interface. The paper then examines several structural, conceptual, and funding barriers that the American private and public sectors face in framing an effective response. These transportation and trade conditions are aptly called "wicked problems," complex problems that sow confusion and fragmentation wherever they arise. The fragmentation that wicked problems create is best faced by increased dialogue and collaboration among key stakeholders. The recommendations for dealing with the critical issues raised here stress the need for better data, the creation of common and compelling overarching goals, and an industrywide commitment to building, educating, and motivating leadership. Three specific recommendations suggest ways that joint public and private cooperation can move the United States forward in transportation policy and practice: develop a national transportation policy framework, prepare an action plan, and set priorities to direct the needed resources and employ the best talent to move the nation's transportation systems from their lagging 20th-century position to a renewed leadership position for the 21st century.
查看更多>>摘要：A public decision by several countries on whether to cofinance an international infrastructure project is the subject of a cost-benefit analysis (CBA). The CBA elements are broken out and analyzed for each country. The issue of freight user benefits is discussed, and results are derived from a partial equilibrium model and point toward practical applicability. A recent analysis of the Fehmarn Belt Bridge, which will connect Denmark and Germany in a link in the Trans-European Network for Transport, is used for illustrative purposes.
Jose Banos-PinoGema Carrera-GomezPablo Coto-MillanVicente Inglada...
p.26-32页
查看更多>>摘要：This study justifies the contemporary importance of efficiency analysis. The theoretical concepts of technical, allocative, and economic efficiency are presented. Empirical problems are addressed, with different ways of measuring efficiency and their inherent disadvantages presented. A theoretical application is given for haulage firms operating on Spanish roads in six subsectors with panel data. The liberalization of goods road transport policies in the 1990s has engendered a more technically efficient reorganization of road transport regions, which will result in innovations in transport services, lower fares, greater diversity in contracts, and better transport quality.
查看更多>>摘要：Findings are presented from a study evaluating sustainable freight distribution in the city center of Dublin, Ireland, particularly focusing on urban distribution centers (UDCs) and managing the last mile of deliveries. A survey of city center organizations is described, and relevant delivery patterns (origin, destination, type of goods delivered) are compared with those from a previous feasibility analysis to determine UDC opportunities in Dublin. A real-life commercial example of a UDC is also described. Ireland's largest grocery distributor operates this UDC. The operational efficiencies and the wider benefits of the UDC are discussed. In addition, a commercial example of managing the last mile of deliveries through a city center delivery platform is detailed. The delivery platform is managed by a leading logistics service provider.
Jose Holguin-VerasJohn PolimeniBrenda CruzNing Xu...
p.42-48页
查看更多>>摘要：This paper summarizes research conducted on private-sector stakeholders' perceptions of the challenges and potential of off-peak deliveries to congested urban areas. Information is presented from a comprehensive outreach program that involved focus groups, in-depth interviews, and Internet surveys. On the basis of the insights gained into the dynamic interactions among stakeholders, the corresponding policy implications and chief conclusions of the research are discussed.
Lee D. HanShih-Miao ChinOscar FranzeseHoling Hwang...
p.49-55页
查看更多>>摘要：Illegal parking of delivery trucks used for pickup and delivery (PUD) reduces traffic capacity and causes delays. A geographically based combinatorial model was developed to estimate the extent of capacity losses and subsequent delays. The model uses a geographically based inference engine to extract data from several large-scale databases and process the data. These data are presented and compared with data from other temporary loss-of-capacity events. Because only weekday and daytime activities were studied, the resulting estimate of the national PUD effect is somewhat conservative.
Seraphim KaprosKonstantinos PanouDimitrios A. Tsamboulas
p.56-63页
查看更多>>摘要：An integrated methodological process was developed to evaluate the expected effect of freight villages. Because the criteria differ as do their measurement units, multicriteria analysis is proposed. The process required an in-depth analysis of the decision-making process for creating a freight village, the operations and the actors involved, and the most recent best practices. The methodology identifies a set of decision criteria, including environmental quality; contributions to local, regional, and national economies; attractiveness for private financing; contribution to land use changes; and complementarity with other policy plans. In addition, the methodology defines the most appropriate corresponding indicators. The identification of stakeholder categories and decision criteria provides added value to the proposed methodological process. The importance of European transport policies on freight villages and terminals development could mean that the process would be the main contributor in developing a pan-European decision tool to assess such investments, especially if private and public funds were involved. The pilot application is an evaluation of investment in a freight village development in northern Greece. The location was selected because it is at the crossroads of important road and rail axes of trans-European transport networks and the interest expressed by the European Commission and Greek private investors.
查看更多>>摘要：This research attempted to build a framework for determining optimal routes for hazardous materials transportation. Previous work has suggested the incorporation of many conflicting objectives in the analysis, such as travel cost, population exposure, environmental risk, and security concerns. Multiplying the number of objectives leads to complex shortest path problems that often have several efficient solutions. The present study emphasizes an overview of possible trade-offs among routes without generating all of them. A simple characterization of the efficient routes is used to select the best ones with no need for input from the decision maker. A case study with eight objective functions was performed on a road network in Singapore. A geographical information system was used to quantify road link attributes, which are assumed linear and deterministic for the sake of simplicity. The proposed algorithm derives four significantly different routes, which conform to intuition.
查看更多>>摘要：Results are presented from a comprehensive analysis of the observed trip chain behavior of commercial vehicles in the Denver, Colorado, region on the basis of data collected by the Denver Regional Council of Governments. These analyses may provide the foundation for further research into commercial vehicle trip chain models. Trip chain behavior is characterized by number of trip chains, length of trip chains, and conditional probability of trip purpose. For this analysis, trip purposes were grouped as freight transportation; transport of people; service calls; fuel, service, and so forth; and return to base or home. Commercial vehicles were grouped as automobile, pickup van, single-unit truck, combination truck, and sports utility vehicle. The conditional probabilities were analyzed for a fixed length of trip chain and were conditioned on stop number. Although most vehicles were found to make one trip chain per day, one of four commercial vehicles made more than one trip chain per day. The analyses also indicated that the average number of stops per trip chain decreased with the number of trip chains. About 35% of the trip chains involved two stops, although some trip chains had more than 12 stops. The main trip purpose for all commercial vehicles was freight transportation, although some vehicles had mixed uses. This study apparently represents the first comprehensive attempt reported in the literature to analyze the observed patterns of commercial vehicle trip chain behavior.
查看更多>>摘要：This research focuses on the frequent and persistent problem of truck shortages for time-sensitive, perishable produce shipment out of the Pacific Northwest. Washington State is the number one apple-producing state in the United States, accounting for more than 2.7 million tons of apples per year valued in excess of $1 billion. However, without timely and accessible transportation to move the product from production to the consumer's table, the value to apple producers and the state's economy diminishes rapidly. This research aims to identify and quantify the change in total transportation cost that occurs as a result of seasonal truck shortages and associated rate increases and to provide an avenue for evaluating changes in specific destination markets, modal changes, and market competitiveness. A cost-minimizing optimization model is used to represent apple shipments from 29 producing supply points to 16 domestic markets and three international export markets over four seasons for two modes (truck and rail). Total transportation costs increase nearly $12 million as a result of truck shortages, from $245.6 million without shortages to $257.5 million under the current seasonal situation. Overall (across all seasons), the export markets of Nogales, Arizona; McAllen, Texas; and the Port of Seattle, Washington, are most affected by the truck shortages, followed by domestic markets near Seattle and San Francisco, California. The large markets of New York City, New York, and Los Angeles, California also experience relatively large increases in transportation cost per ton mile.
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